Whether you're an avid cyclist, an occasional spin class warrior or are considering your first ride there are four spin instructors in SF that you want to know: Andrew Stinger, Marcia Robles, Danny Baker and Caroline Jordan. These four "Spin Ninjas" have uniquely different styles and while different are all grounded in safety, effectiveness and kick ass energy. Each was was kind enough to share with me how to avoid the most common and dangerous form issues; how to overcome common mental challenges; and their take on how often someone "should" spin, intervals-vs-steady state and what to do in between rides.